The Urban Dictionary Mug

This phrase came about because of teenagers feeling the need to have a big stereo. They would buy twin 10" sub 300w car bass systems and hook them up in their bedrooms and it would shake the house, and the floors.

Usually the synonym "ROFL" is used, denoting "Rolling On Floor Laughing" to express humour. In the case of loud bass music playing at the time, the person would be rolling on the floor and vibrating instead of laughing.